Progressive spectacle lens having a variable refractive index and method for the design and production thereof

Abstract

A progressive spectacle lens has a front face and a rear face and a uniform substrate with a locally varying refractive index. The front face and/or the rear face of the substrate is formed as a free-form surface and carries only functional coatings, if any. The refractive index varies (a) only in a first spatial dimension and in a second spatial dimension and is constant in a third spatial dimension, a distribution of the refractive being neither point-symmetrical nor axis symmetrical, or (b) in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, a distribution of the refractive index being neither point-symmetrical nor axis symmetrical, or (c) in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, a distribution of the refractive index not being point-symmetrical or axis symmetrical at all.

The invention claimed is: 
     
       1. A product comprising:
 (i) a progressive power spectacle lens or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a non-transitory data medium as computer-readable data, or (iii) a non-transitory data medium with a virtual representation of the progressive power spectacle lens as computer-readable data having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens includes: 
 a uniform substrate having a spatially varying refractive index, a front surface, and a back surface, 
 wherein, during use as intended, the front surface and the back surface either jointly form outer surfaces of the progressive power spectacle lens or at least one of the front surface or the back surface is exclusively provided with one or more functional coatings which do not contribute or at each point contribute less than 0.004 dpt to a spherical equivalent of a dioptric power of the progressive power spectacle lens, 
 wherein at least one of the front surface is or the back surface is configured as a freeform surface, 
 wherein
 (a) the refractive index varies in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, wherein a distribution of the refractive index in the first spatial dimension and the second spatial dimension in all planes perpendicular to the third spatial dimension has neither point symmetry nor axial symmetry. 
 
 
     
     
       2. The product as claimed in  claim 1 , wherein the product comprises a zero viewing direction during use as intended and wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the zero viewing direction during use as intended or 
 differs by not more than 10° from the zero viewing direction during use as intended or 
 differs by not more than 20° from the zero viewing direction during use as intended. 
 
     
     
       3. The product as claimed in  claim 1 , wherein the product comprises a principal viewing direction during use as intended and wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the principal viewing direction during use as intended or 
 differs by not more than 10° from the principal viewing direction during use as intended or 
 differs by not more than 20° from the principal viewing direction during use as intended. 
 
     
     
       4. The product as claimed in  claim 1 , wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the direction of the normal vector of the front surface in the geometric center of the progressive power spectacle lens or 
 differs by not more than 10° from the direction of the normal vector of the front surface in the geometric center of the progressive power spectacle lens or 
 differs by not more than 20° from the direction of the normal vector of the front surface in the geometric center of the progressive power spectacle lens. 
 
     
     
       5. The product as claimed in  claim 1 , wherein the product comprises a prismatic measurement point and wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the direction of the normal vector at the prismatic measurement point or 
 differs by not more than 10° from the direction of the normal vector at the prismatic measurement point or 
 differs by not more than 20° from the direction of the normal vector at the prismatic measurement point. 
 
     
     
       6. The product as claimed in  claim 1 , wherein the product comprises a centration point and wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the direction of the normal vector at the centration point or 
 differs by not more than 10° from the direction of the normal vector at the centration point or 
 differs by not more than 20° from the direction of the normal vector at the centration point. 
 
     
     
       7. The product as claimed in  claim 1 , wherein
 (i) the front surface is configured as the freeform surface, wherein a maximum of an absolute value of a mean curvature of the front surface is in an intermediate corridor, and/or 
 (ii) the back surface is configured as the freeform surface, wherein a minimum of the absolute value of the mean curvature of the back surface is in the intermediate corridor, or 
 (iii) the back surface has a spherical, rotationally symmetrically aspheric, or toric surface geometry or is a surface having two planes of symmetry and the front surface is configured as the freeform surface, wherein the maximum of the absolute value of the mean curvature of the front surface is in the intermediate corridor, or 
 (iv) the front surface has a spherical, rotationally symmetrically aspheric, or toric surface geometry or is a surface having two planes of symmetry and the back surface is configured as the freeform surface, wherein the minimum of the absolute value of the mean curvature of the back surface is in the intermediate corridor, or 
 (v) the back surface is not configured as the freeform surface and the front surface is configured as the freeform surface, wherein the maximum of the absolute value of the mean curvature of the front surface is in the intermediate corridor, or 
 (vi) the front surface is not configured as the freeform surface and the back surface is configured as the freeform surface, wherein the minimum of the absolute value of the mean curvature of the back surface is in the intermediate corridor. 
 
     
     
       8. The product as claimed in  claim 1 , further comprising:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, or (ii) the non-transitory data medium with the computer-readable data concerning the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has a distribution of a spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has an intermediate corridor with a width and the refractive index of the progressive power spectacle lens varies in space such that the width of the intermediate corridor of the progressive power spectacle lens, at least in a section or over the entire length of the intermediate corridor, is greater than the width of the intermediate corridor in the at least one section or over the entire length of the intermediate corridor of a comparison progressive power spectacle lens with a same distribution of the spherical equivalent in the case of a same arrangement of the comparison progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, but with a spatially non-varying refractive index. 
 
     
     
       9. The product as claimed in  claim 8 , wherein a variant of the group:
 horizontal section, 
 section at half addition, 
 horizontal section at half addition, 
 horizontal section at half addition, 
 horizontal section at 25% of the addition, 
 horizontal section at 75% of the addition, 
 horizontal section at half addition and horizontal section at 25% of the addition, 
 horizontal section at half addition and horizontal section at 75% of the addition, 
 horizontal section at half addition and horizontal section at 25% of the addition and horizontal section at 75% of the addition, 
 
       is chosen for the at least one section. 
     
     
       10. The product as claimed in  claim 8 , further comprising:
 (i) a representation, situated on the non-transitory data medium as the computer-readable data, of a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (ii) a representation, situated on the non-transitory data medium as the computer-readable data, of an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iii) a representation, situated on the non-transitory data medium as the computer-readable data, of a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iv) a representation, situated on the non-transitory data medium as the computer-readable data, of a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (v) the non-transitory data medium having the computer-readable data concerning a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vi) the non-transitory data medium having the computer-readable data concerning an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vii) the non-transitory data medium having the computer-readable data concerning a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (viii) the non-transitory data medium having the computer-readable data concerning a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has a distance portion and a near portion, and in that 
 wherein the width of the intermediate corridor corresponds to the dimension transverse to a longitudinal direction of the intermediate corridor extending between the distance portion and near portion, within which the absolute value of the residual astigmatism lies below a predetermined limit value, which is selected within a range from the group specified below: 
 (a) the limit value lies in the range between 0.25 dpt and 1.5 dpt, 
 (b) the limit value lies in the range between 0.25 dpt and 1.0 dpt, 
 (c) the limit value lies in the range between 0.25 dpt and 0.75 dpt, 
 (d) the limit value lies in the range between 0.25 dpt and 0.6 dpt, 
 (e) the limit value lies in the range between 0.25 dpt and 0.5 dpt, 
 (f) the limit value is 0.5 dpt. 
 
     
     
       11. The product as claimed in  claim 1 , further comprising:
 (i) a representation, situated on the non-transitory data medium as the computer-readable data, of a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, or (ii) the non-transitory data medium having the computer-readable data concerning a predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has a distribution of a spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, in that 
 wherein the product further includes: 
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (ii) a representation, situated on the non-transitory data medium as the computer-readable data, of an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iii) a representation, stored on the non-transitory data medium as the computer-readable data, of a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iv) a representation, stored on a data medium in the form of computer-readable data, of a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (v) the non-transitory data medium having the computer-readable data concerning a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vi) the non-transitory data medium having the computer-readable data concerning an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vii) the non-transitory data medium having the computer-readable data concerning a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (viii) the non-transitory data medium having the computer-readable data concerning a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and
 wherein the refractive index of the progressive power spectacle lens varies in space such that a maximum value of a residual astigmatism of the progressive power spectacle lens is less than the maximum value of the residual astigmatism of a comparison progressive power spectacle lens with a same distribution of the spherical equivalent in the case of a same arrangement of the comparison progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, but with a spatially non-varying refractive index. 
 
 
     
     
       12. The product as claimed in  claim 1 , further comprising:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, or (ii) the non-transitory data medium having the computer-readable data concerning the predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has a distribution of a spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the product further includes: 
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (ii) a representation, stored on the non-transitory data medium as the computer-readable data, of an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iii) a representation, stored on the non-transitory data medium as the computer-readable data, of a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iv) a representation, stored on the non-transitory data medium as the computer-readable data, of a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (v) the non-transitory data medium having the computer-readable data concerning a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vi) the non-transitory data medium having the computer-readable data concerning an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vii) the non-transitory data medium having the computer-readable data concerning a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (viii) the non-transitory data medium having the computer-readable data concerning a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens includes an intermediate corridor and a principal line of sight, and where in the refractive index of the progressive power spectacle lens varies in space such that for a predetermined residual astigmatism value A res,lim  of the group 
 (a) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 1.5 dpt, 
 (b) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 1.0 dpt, 
 (c) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 0.75 dpt, 
 (d) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 0.6 dpt, 
 (e) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 0.5 dpt, 
 (f) the residual astigmatism value A res,lim  is 0.5 dpt 
 
       on a horizontal section at a narrowest point of the intermediate corridor or for a horizontal section through a point on the principal line of sight at which the half addition is achieved, the following relationship applies within a region with a horizontal distance of 10 mm on both sides of the principal line of sight: 
       
         
           
             
               B 
               > 
               
                 c 
                 × 
                 
                   
                     A 
                     
                       res 
                       , 
                       lim 
                     
                   
                   
                     grad 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     W 
                   
                 
               
             
           
         
       
       wherein grad W describes the power gradient of the spherical equivalent in the direction of the principal line of sight of the progressive power spectacle lens at the narrowest point of the intermediate corridor on the principal line of sight or in a point on the principal line of sight at which the half addition is achieved, B describes the width of the region in the progressive power spectacle lens in which the residual astigmatism is A res ≤A res,lim , where c is a constant selected from the group:
 (a) 1.0<c, 
 (b) 1.1<c, 
 (c) 1.2<c, or 
 (d) 1.3<c. 
 
     
     
       13. A method for producing, by way of an additive method, a progressive power spectacle lens as claimed in  claim 1 . 
     
     
       14. A product comprising: (i) a progressive power spectacle lens or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a non-transitory data medium as computer-readable data, or (iii) a non-transitory data medium with a virtual representation of the progressive power spectacle lens as computer-readable data having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens includes:
 a uniform substrate having a spatially varying refractive index, a front surface, and a back surface, 
 wherein, during use as intended, the front surface and the back surface either jointly form outer surfaces of the progressive power spectacle lens or at least one of the front surface or the back surface is exclusively provided with one or more functional coatings which do not contribute or at each point contribute less than 0.004 dpt to a spherical equivalent of a dioptric power of the progressive power spectacle lens, 
 wherein at least one of the front surface or the back surface is configured as a freeform surface, wherein 
 (c) the refractive index varies in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, wherein a distribution of the refractive index has no point symmetry and no axial symmetry at all. 
 
     
     
       15. A product comprising:
 (i) a progressive power spectacle lens or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a non-transitory data medium as computer-readable data, or (iii) the non-transitory data medium having a virtual representation of the progressive power spectacle lens as computer-readable data and having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens has: 
 a front surface; 
 a back surface; and 
 a spatially varying refractive index, 
 wherein at least one of the front surface or the back surface is configured as a freeform surface, the freeform surface being configured as a progressive surface, 
 wherein the progressive power spectacle lens is made of a substrate having no individual layers and having the front surface, the back surface, and the spatially varying refractive index, 
 wherein the substrate has at least one of a front surface coating including one or more individual layers or a back surface coating including one or more individual layers, 
 wherein a difference between the spherical equivalent measured at each point on the front surface of the progressive power spectacle lens with the at least one of the front surface coating or the back surface coating and the spherical equivalent measured at each corresponding point on the front surface of a comparison progressive power spectacle lens without the front surface coating and without the back surface coating but with an identical substrate is less than a value from the group specified below:
 (a) the difference value is less than 0.001 dpt 
 (b) the difference value is less than 0.002 dpt 
 (c) the difference value is less than 0.003 dpt 
 (d) the difference value is less than 0.004 dpt 
 
 and wherein
 (b) the refractive index varies in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, wherein the distribution of the refractive index in the first spatial dimension and the second spatial dimension in all planes perpendicular to the third spatial dimension has neither point symmetry nor axial symmetry. 
 
 
     
     
       16. The product as claimed in  claim 15 , further comprising a zero viewing direction during use as intended, wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the zero viewing direction during use as intended or 
 differs by not more than 10° from the zero viewing direction during use as intended or 
 differs by not more than 20° from the zero viewing direction during use as intended. 
 
     
     
       17. The product as claimed in  claim 15 , further comprising a principal viewing direction during use as intended, wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the principal viewing direction during use as intended or 
 differs by not more than 10° from the principal viewing direction during use as intended or 
 differs by not more than 20° from the principal viewing direction during use as intended. 
 
     
     
       18. The product as claimed in  claim 15 , wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the direction of the normal vector of the front surface in the geometric center of the progressive power spectacle lens or 
 differs by not more than 10° from the direction of the normal vector of the front surface in the geometric center of the progressive power spectacle lens or 
 differs by not more than 20° from the direction of the normal vector of the front surface in the geometric center of the progressive power spectacle lens. 
 
     
     
       19. The product as claimed in  claim 15 , further comprising a prismatic measurement point, wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the direction of the normal vector at the prismatic measurement point or 
 differs by not more than 10° from the direction of the normal vector at the prismatic measurement point or 
 differs by not more than 20° from the direction of the normal vector at the prismatic measurement point. 
 
     
     
       20. The product as claimed in  claim 15 , further comprising a centration point, wherein the third spatial dimension in case (a) extends in a direction which
 differs by not more than 5° from the direction of the normal vector at the centration point or 
 differs by not more than 10° from the direction of the normal vector at the centration point or 
 differs by not more than 20° from the direction of the normal vector at the centration point. 
 
     
     
       21. The product as claimed in  claim 15 , wherein the progressive power spectacle lens further comprises an intermediate corridor, wherein
 (i) the front surface is configured as the freeform surface, wherein the mean curvature has a maximum in the intermediate corridor, and/or 
 (ii) the back surface is configured as the freeform surface, wherein the mean curvature has a minimum in the intermediate corridor, or 
 (iii) the back surface has a spherical, rotationally symmetrically aspheric, or toric surface geometry and the front surface is configured as the freeform surface, wherein the maximum of the absolute value of the mean curvature of the front surface is in the intermediate corridor, or 
 (iv) the front surface has a spherical, rotationally symmetrically aspheric, or toric surface geometry and the back surface is configured as the freeform surface, wherein the minimum of the absolute value of the mean curvature of the back surface is in the intermediate corridor, or 
 (v) the back surface is not configured as the freeform surface and the front surface is configured as the freeform surface, wherein the maximum of the absolute value of the mean curvature of the front surface is in the intermediate corridor, or 
 (vi) the front surface is not configured as the freeform surface and the back surface is configured as the freeform surface, wherein the minimum of the absolute value of the mean curvature of the back surface is in the intermediate corridor. 
 
     
     
       22. The product as claimed in  claim 15 , further comprising:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, or (ii) the non-transitory data medium having the computer-readable data concerning a predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer,
 wherein the progressive power spectacle lens has a distribution of a spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has an intermediate corridor with a width and the refractive index of the progressive power spectacle lens varies in space such that the width of the intermediate corridor of the progressive power spectacle lens, at least in a section or over the entire length of the intermediate corridor, is greater than the width of the intermediate corridor of a comparison progressive power spectacle lens with a same distribution of the spherical equivalent in the case of a same arrangement of the comparison progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, but with a spatially non-varying refractive index. 
 
 
     
     
       23. The product as claimed in  claim 22 , wherein a variant of the group:
 horizontal section, 
 section at half addition, 
 horizontal section at half addition, 
 horizontal section at half addition and horizontal section at 25% of the addition, 
 horizontal section at half addition and horizontal section at 75% of the addition, 
 horizontal section at half addition and horizontal section at 25% of the addition and horizontal section at 75% of the addition, 
 is chosen for the at least one section. 
 
     
     
       24. The product as claimed in  claim 22 , further comprising:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (ii) a representation, stored on the non-transitory data medium as the computer-readable data, of an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iii) a representation, stored on the non-transitory data medium as the computer-readable data, of a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iv) a representation, stored on the non-transitory data medium as the computer-readable data, of a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (v) the non-transitory data medium having the computer-readable data concerning a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vi) the non-transitory data medium having the computer-readable data concerning an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vii) the non-transitory data medium having the computer-readable data concerning a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (viii) the non-transitory data medium having the computer-readable data concerning a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has a distance portion and a near portion, and 
 wherein the width of the intermediate corridor corresponds to the dimension transverse to a longitudinal direction of the intermediate corridor extending between the distance portion and near portion, within which the absolute value of the residual astigmatism lies below a predetermined limit value, which is selected within a range from the group specified below: 
 (a) the limit value lies in the range between 0.25 dpt and 1.5 dpt, 
 (b) the limit value lies in the range between 0.25 dpt and 1.0 dpt, 
 (c) the limit value lies in the range between 0.25 dpt and 0.75 dpt, 
 (d) the limit value lies in the range between 0.25 dpt and 0.6 dpt, 
 (e) the limit value lies in the range between 0.25 dpt and 0.5 dpt, 
 (f) the limit value is 0.5 dpt. 
 
     
     
       25. The product as claimed in  claim 15 , further comprising:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, or (ii) the non-transitory data medium having computer-readable data concerning a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, 
 wherein the progressive power spectacle lens has a distribution of a spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the product further includes:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (ii) a representation, stored on the non-transitory data medium as the computer-readable data, of an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iii) a representation, stored on the non-transitory data medium as the computer-readable data, of a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iv) a representation, stored on the non-transitory data medium as the computer-readable data, of a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (v) the non-transitory data medium having computer-readable data concerning a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vi) the non-transitory data medium having computer-readable data concerning an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vii) the non-transitory data medium having computer-readable data concerning a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (viii) the non-transitory data medium having computer-readable data concerning a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the refractive index of the progressive power spectacle lens varies in space such that the maximum value of the residual astigmatism of the progressive power spectacle lens is less than the maximum value of the residual astigmatism of a comparison progressive power spectacle lens with a same distribution of the spherical equivalent in the case of a same arrangement of the comparison progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, but with a spatially non-varying refractive index. 
 
 
     
     
       26. The product as claimed in  claim 15 , further comprising:
 (i) a representation, stored on the non-transitory data medium as computer-readable data, of a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, or (ii) the non-transitory data medium having computer-readable data concerning a predetermined arrangement of the progressive power spectacle lens in front of an eye of a progressive power spectacle wearer, 
 wherein the progressive power spectacle lens has a distribution of a spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, in that 
 the product further includes:
 (i) a representation, stored on the non-transitory data medium as the computer-readable data, of a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (ii) a representation, stored on the non-transitory data medium as the computer-readable data, of an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iii) a representation, stored on the non-transitory data medium as the computer-readable data, of a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (iv) a representation, stored on the non-transitory data medium as the computer-readable data, of a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (v) the non-transitory data medium having computer-readable data concerning a residual astigmatism distribution for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vi) the non-transitory data medium having computer-readable data concerning an astigmatic power distribution, required for a full correction, for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (vii) the non-transitory data medium having computer-readable data concerning a prescription and an object distance model for the predetermined arrangement of the progressive power spectacle lens in front of the eye of a progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, and/or 
 (viii) the non-transitory data medium having computer-readable data concerning a distribution of the spherical equivalent for the predetermined arrangement of the progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, for whom the progressive power spectacle lens is intended, 
 wherein the progressive power spectacle lens has an intermediate corridor and a principal line of sight, and wherein the refractive index of the progressive power spectacle lens varies in space such that for a predetermined residual astigmatism value A res,lim  of the group 
 (a) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 1.5 dpt, 
 (b) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 1.0 dpt, 
 (c) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 0.75 dpt, 
 (d) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 0.6 dpt, 
 (e) the residual astigmatism value A res,lim  lies in the range between 0.25 dpt and 0.5 dpt, 
 (f) the residual astigmatism value A res,lim  is 0.5 dpt 
 
 
       on a horizontal section at a narrowest point of the intermediate corridor or for a horizontal section through the point on the principal line of sight at which the half addition is achieved, the following relationship applies within a region with a horizontal distance of 10 mm on both sides of the principal line of sight: 
       
         
           
             
               B 
               > 
               
                 c 
                 × 
                 
                   
                     A 
                     
                       res 
                       , 
                       lim 
                     
                   
                   
                     grad 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     W 
                   
                 
               
             
           
         
       
       wherein grad W describes a power gradient of the spherical equivalent of the progressive power spectacle lens at the narrowest point of the intermediate corridor on the principal line of sight or in thr point on the principal line of sight at which the half addition is achieved, B describes the width of the region in the progressive power spectacle lens in which the residual astigmatism is A res ≤A res,lim , wherein c is a constant selected from the group:
 (a) 1.0<c, 
 (b) 1.1<c, 
 (c) 1.2<c, or 
 (d) 1.3<c. 
 
     
     
       27. A product comprising:
 (i) a progressive power spectacle lens or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a data medium as computer-readable data, or (iii) the non-transitory data medium having a virtual representation of the progressive power spectacle lens as the computer-readable data and having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens has: 
 a front surface; 
 a back surface; and 
 a spatially varying refractive index, 
 wherein at least one of the front surface or the back surface is configured as a freeform surface, wherein the freeform surface is configured as a progressive surface, 
 wherein the progressive power spectacle lens is made of a substrate having no individual layers and having the front surface, the back surface, and the spatially varying refractive index, 
 wherein the substrate has at least one of a front surface coating including one or more individual layers or a back surface coating including one or more individual layers, 
 wherein a difference between a spherical equivalent measured at each point on the front surface of the progressive power spectacle lens with the at least one of the front surface coating or the back surface coating and the spherical equivalent measured at each corresponding point on the front surface of a comparison progressive power spectacle lens without the front surface coating and without the back surface coating but with an identical substrate is less than a value from the group specified below:
 (a) the difference value is less than 0.001 dpt 
 (b) the difference value is less than 0.002 dpt 
 (c) the difference value is less than 0.003 dpt 
 (d) the difference value is less than 0.004 dpt 
 
 and wherein
 (c) the refractive index varies in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, wherein a distribution of the refractive index has no point symmetry and no axial symmetry at all. 
 
 
     
     
       28. A computer-implemented method for designing a progressive power spectacle lens having a front surface, a back surface, and a spatially varying refractive index, wherein at least one of the front surface or the back surface is configured as a progressive surface, the method comprising:
 calculating optical properties of the progressive power spectacle lens with a ray tracing method at a plurality of evaluation points, at which visual rays pass through the progressive power spectacle lens; 
 setting at least one intended optical property for the progressive power spectacle lens at the respective evaluation point; 
 setting a design for the progressive power spectacle lens, wherein the design includes a representation of a local surface geometry of the progressive surface and a local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points; 
 modifying the design of the progressive power spectacle lens in view of an approximation of the at least one intended optical property of the progressive power spectacle lens, wherein the modifying includes modifying the representation of the local surface geometry of the progressive surface and the local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points, wherein the at least one intended optical property includes an intended residual astigmatism of the progressive power spectacle lens, wherein the progressive surface and the local refractive index are modified according to at least one of the specifications from the following group of specifications: 
 (i) the progressive surface is modified freely in two spatial dimensions and the local refractive index is modified freely in at least two spatial dimensions, 
 (ii) the progressive surface is modified freely in one or in two spatial dimensions and the local refractive index is modified freely in three spatial dimensions, 
 (iii) the progressive surface is modified freely in two spatial dimensions and the local refractive index is modified freely in two spatial dimensions, and 
 (iv) the progressive surface is modified freely in two spatial dimensions and the local refractive index is modified freely in three spatial dimensions. 
 
     
     
       29. The method as claimed in  claim 28 , wherein the progressive surface is modified such that a freeform surface arises which has neither point symmetry nor axial symmetry, and
 wherein the local refractive index is modified such that:
 (a) the refractive index varies only in a first spatial dimension and in a second spatial dimension, and is constant in a third spatial dimension, such that a distribution of the refractive index in the first spatial dimension and the second spatial dimension has neither point symmetry nor axial symmetry, or 
 (b) the refractive index varies in the first spatial dimension, the second spatial dimension, and the third spatial dimension, such that a distribution of the refractive index in the first spatial dimension and the second spatial dimension in all planes perpendicular to the third spatial dimension has neither point symmetry nor axial symmetry, or 
 (c) the refractive index varies in the first spatial dimension, the second spatial dimension, and the third spatial dimension, such that a distribution of the refractive index in the progressive power spectacle lens has no point symmetry and no axial symmetry at all. 
 
 
     
     
       30. The method as claimed in  claim 28 , wherein the at least one intended optical property of the progressive power spectacle lens is derived
 (i) from a corresponding intended optical property for a progressive power spectacle lens with a spatially non-varying refractive index and/or 
 (ii) from a corresponding optical property of a progressive power spectacle lens with a spatially non-varying refractive index, 
 or wherein the intended residual astigmatism of the progressive power spectacle lens is derived 
 (i) from an intended residual astigmatism for a progressive power spectacle lens with a spatially non-varying refractive index and/or 
 (ii) from a residual astigmatism of a progressive power spectacle lens with a spatially non-varying refractive index. 
 
     
     
       31. The method as claimed in  claim 30 , wherein the at least one intended optical property of the progressive power spectacle lens in a central intermediate portion between the distance portion and the near portion is reduced vis-à-vis
 (i) the corresponding intended optical property for the progressive power spectacle lens with a spatially non-varying refractive index or 
 (ii) the corresponding optical property of the progressive power spectacle lens with a spatially non-varying refractive index, 
 
       or wherein the intended residual astigmatism of the progressive power spectacle lens in a central intermediate portion between distance portion and near portion is reduced vis-à-vis
 (i) the intended residual astigmatism for the progressive power spectacle lens with a spatially non-varying refractive index or 
 (ii) the residual astigmatism of the progressive power spectacle lens with a spatially non-varying refractive index. 
 
     
     
       32. The method as claimed in  claim 31 , wherein the intended residual astigmatism of the progressive power spectacle lens in a central intermediate portion between distance portion and near portion is reduced in a region around the principal line of sight, and wherein the region comprises a horizontal distance on both sides from the group
 (a) 5 mm from the principal line of sight, 
 (b) 10 mm from the principal line of sight, or 
 (c) 20 mm from the principal line of sight. 
 
     
     
       33. The method as claimed in  claim 28 , wherein the modification of the design of the progressive power spectacle lens is implemented in view of a minimization of a target function 
       
         
           
             
               F 
               = 
               
                 
                   ∑ 
                   m 
                 
                 ⁢ 
                 
                   
                     ∑ 
                     n 
                   
                   ⁢ 
                   
                     
                       
                         W 
                         n 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           
                             T 
                             n 
                             m 
                           
                           - 
                           
                             A 
                             n 
                             m 
                           
                         
                         ) 
                       
                     
                     2 
                   
                 
               
             
           
         
         where W n   m  represents the weighting of the optical property n at the evaluation point m, T n   m  represents the intended value of the optical property n at the evaluation point m, and A n   m  represents the actual value of the optical property n at the evaluation point m. 
       
     
     
       34. The method as claimed in  claim 28 , wherein an intended residual astigmatism is predetermined for at least one evaluation point, the intended residual astigmatism being less than the theoretically achievable residual astigmatism at the at least one corresponding evaluation point on a comparison progressive power spectacle lens with the same distribution of the spherical equivalent and the same arrangement of the comparison progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, but with a spatially non-varying refractive index, and in that modifying the representation of the local surface geometry of the progressive surface and of the local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points is only terminated if the residual astigmatism at the at least one evaluation point, achieved for the designed progressive power spectacle lens, is less than the theoretically achievable residual astigmatism at the at least one corresponding evaluation point on the comparison progressive power spectacle lens. 
     
     
       35. The method as claimed in  claim 28 , wherein modifying the representation of the local surface geometry of the progressive surface and of the local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points is implemented with the stipulation that the maximum value of the residual astigmatism of the progressive power spectacle lens is less than the maximum value of the residual astigmatism of a comparison progressive power spectacle lens with the same distribution of the spherical equivalent and the same arrangement of the comparison progressive power spectacle lens in front of the eye of the progressive power spectacle wearer, but with a spatially non-varying refractive index. 
     
     
       36. The method as claimed in  claim 28 , wherein designing the progressive power spectacle lens results in a progressive power spectacle lens comprising:
 (i) a progressive power spectacle lens or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a non-transitory data medium as computer-readable data, or (iii) a non-transitory data medium with a virtual representation of the progressive power spectacle lens as computer-readable data having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens includes: 
 a uniform substrate having a spatially varying refractive index, a front surface, and a back surface, 
 wherein, during use as intended, the front surface and the back surface either jointly form outer surfaces of the progressive power spectacle lens or at least one of the front surface or the back surface is exclusively provided with one or more functional coatings which do not contribute or at each point contribute less than 0.004 dpt to a spherical equivalent of a dioptric power of the progressive power spectacle lens, 
 wherein at least one of the front surface is or the back surface is configured as a freeform surface, 
 wherein the refractive index varies in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, wherein a distribution of the refractive index in the first spatial dimension and the second spatial dimension in all planes perpendicular to the third spatial dimension has neither point symmetry nor axial symmetry. 
 
     
     
       37. A computer program having program code for carrying out all method steps as claimed in  claim 28  when the computer program is loaded on a computer and/or executed on a computer. 
     
     
       38. A computer-readable medium comprising a computer program as claimed in  claim 37 . 
     
     
       39. A method for producing a progressive power spectacle lens, comprising a method as claimed in  claim 28  and manufacturing of the progressive power spectacle lens according to the design. 
     
     
       40. The method as claimed in  claim 39 , wherein the progressive power spectacle lens is manufactured using an additive method. 
     
     
       41. A computer having a processor and a non-transitory memory in which a computer program as claimed in  claim 37  is stored, the computer being configured to carry out a method comprising:
 calculating optical properties of the progressive power spectacle lens with a ray tracing method at a plurality of evaluation points, at which visual rays pass through the progressive power spectacle lens; 
 setting at least one intended optical property for the progressive power spectacle lens at the respective evaluation point; 
 setting a design for the progressive power spectacle lens, wherein the design includes a representation of a local surface geometry of the progressive surface and a local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points; 
 modifying the design of the progressive power spectacle lens in view of an approximation of the at least one intended optical property of the progressive power spectacle lens, wherein the modifying includes modifying the representation of the local surface geometry of the progressive surface and the local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points, wherein the at least one intended optical property includes an intended residual astigmatism of the progressive power spectacle lens, wherein the progressive surface and the local refractive index are modified according to at least one of the specifications from the following group of specifications: 
 (i) the progressive surface is modified freely in two spatial dimensions and the local refractive index is modified freely in at least two spatial dimensions, 
 (ii) the progressive surface is modified freely in one or in two spatial dimensions and the local refractive index is modified freely in three spatial dimensions, 
 (iii) the progressive surface is modified freely in two spatial dimensions and the local refractive index is modified freely in two spatial dimensions, and 
 (iv) the progressive surface is modified freely in two spatial dimensions and the local refractive index is modified freely in three spatial dimensions.